Permanent waving compositions and methods



Patented Dec. 4, 1951 PERMANENT WAVING COMPOSITIONS AND METHODS Everett G. McDonough, Yonkers, N. Y., assignor, by mesne assignments, to The Procter and Gamble Company, Cincinnati, Ohio, a corporation of Ohio No Drawing. Application June 16, 1941,

Serial No. 398,235

18 Claims. (Cl. 132-7) More particularly, in permanent waving the mechanical force is set up by winding the hair in curls as on m-andrels. A chemical medium is then (or previously) applied to create the chemical or softening force adapted to place the wound tresses in condition to be permanently molded and altered to their new form as determined by the winding. Finally, means are utilized to fix the wound tresses in their new form, which latter means may consist of an application of heat, generated electrically, chemically or in any other way followed by cooling or a second chemically reactive force to neutralize the chemical waving medium.

The present invention is concerned with the chemical medium which provides the chemical or softening force above referred to, this being identified hereinafter for descriptive purposes only as the waving solution, and comprising an aqueous solution containing the waving agent or agents.

Heretofore, the practicehas been to use a waving agent for such solutions which is an al kaline material, for example, bor-ax, various carbonates and phosphates of alkaline materials, ammonia and ammonium salts, such as the carbonates. Furthermore, soluble sulfites of alkalies and ammonia have been utilized for the waving agent, and sulfides have also been provided for this purpose.

However, with respect to the sulfites and to all other heretofore utilized waving agents excepting sulfides, relatively high concentrations are necessary in order to obtain any satisfactory permanent wave in the hair. Especially with fine hair, there is difilculty in providing a suitable waving solution for obtaining an altered form or shape for the hair which can be termed permanent.

I have found that there is a limiting concentration of these materials above which either hair destruction or injury occurs with less satisfactory wave. It is probably this upward limiting effect on concentration of these waving agents that make it impossible to obtain satisfactory results in a short time where the hair is set by a chemical force, for the solution containing these waving agents must be left in contact with the hair for periods ranging from four to twenty-four hours before a satisfactory wave may be obtained.

The sulfides do not require as long a time nor need quite as great a concentration as the sulfites and a satisfactory solution may be made therefrom for most types of hair and even fine hair under some conditions, but many disadvantages appear when using sulfides, the first of which is the characteristic odor of rotten eggs possessed by such sulfides resulting from generation and liberation of free hydrogen sulfide by hydrolysis. All attempts to mask this odor result in failure and the use of heavy perfumes only serves to minimize the objectionable odor. Secondly, these sulfides have a tendency to cause tarnishing and blackening on metal, particularly jewelry, silverware, and the like, which is a further objection to their use in the waving lotion. Furthermore, the disgusting odor which accompanies the use of such hydrogen sulfide salts is toxic to breathe and although normally the amount of hydrogen sulfide produced thereby is not dangerous, when in a confined booth or room such as a beauty shop cubicle often used in hair waving establishments, the concentration of the gas may become so high as to seriously affect both operator and patron, unless expensive ventilating equipment is installed and maintained to remove this gas.

Thus, it will be seen that, while these sulfides are satisfactory in use in waving solutions from the point of view of performance or results in the finished permanent wave, they are wholly unsatisfactory because of the combined efiect of toxicity, nauseating odor, and metallic coating effect.

More specifically, one of the best waving agents known for use when carrying out a permanent change of form or shape of the hair is ammonium hydrogen sulfide: but, despite its relatively greater waving power, the use thereof is limited by liberation of hydro en sulfide gas, together with ammonia gas. These evolved gases make this compound very objectionable and perhaps dangerous, unless special precautions to remove the vapors, for instance, by suction ventilators.

; are taken.

Another objection to use of ammonium hydrogen sulfide and other sulfides is that the hair tends to retain the sulfide in spite of repeated rinsings even when using a chemical setting solution. The result is a malodor to the hair, particularly on each re-wetting. More important, however, is the fact that this retention by the hair of the sulfide affords a continuous "relaxing" effect on the permanent wave with the result that the wave becomes less tight with each re-wetting.

It is the general objective of this invention to provide an agent for use in altering the permanent form or shape of hair which will be similar in its effect to that of the sulfides referred to above and yet will not possess the great disadvantages mentioned.

It is a further object of this invention to provide a lotion for the permanent waving of hair containing an entirely novel ingredient as the waving agent which will give the solution a wide range of adaptability for permanent waving of any type or texture of hair.

It is a further object of this invention to provide a non-odorous, non-toxic hair waving solution adapted to more rapidly and more success? fully place hair in a condition to be altered in form or shape permanently, irrespective of whether cooling subsequent to heating or chemical means is used after applying the waving solution in order to fix the hair in its new configuration.

It is a further object of this invention to provide a waving solution suitable for that type of permanent waving of hair which utilizes a chemical action for the fixing of the hair in its wound form, such waving solution containing a waving agent as powerful, rapid and satisfactory as ammonium hydrogen sulfide, but free from the limitations of ammonium hydrogen sulfide, particularly the bad odor and toxicity.

It is a further object'of this invention to pro-'- vide a waving solution powerful enough to wave hair without the need of added heat and which can be neutralized or completely removed by water alone; or, in other words, the wave can be fixed in the hair by washing out the waving agent with water alone.

By this invention there is provided an agent for use in the permanent reforming of hair which is fast in action, satisfactory in use for all types of hair and yet is free from objectionable odors or toxicity or the like.

I have discovered that I can obtain these objects by providing as a waving agent a mercaptan, or a mixture of mercaptans, whether the fixing of the new form for the hairbe by cooling subsequent to heating, or by using .chemical rinses or by any other method, and, further, that an effective waving solution can be obtained by proper formulation including a mercaptan in water. The mercaptans are represented by the formula R-SH where R is an organic group such .as the ethyl group in H H Ethyl mercaptan or the benzyl group in Benzyl mercaptan Such simple mercaptans will function adequately .as waving agents, butthey still have the disadvantage of sulfides, such as ammonium hydrogen sulfide as far as bad odor isconcerned. I .have discovered that bad odor, and other dis,-

vadvantages can. be entirely obviated by having ,the molecule contain other groups which are carefully selected,,as hereinafter set forth, to give 'of polar acidic substituted mercaptans are: mercaptans containing the carboxylic groups, as, for

example; the simple mercapto-alka'noic' acid,

.ing agents-when used in solutions.

mercapto-acetic acid (thioglycollic), mercaptans containing sulfonic groups, as, for example, mercapto-ethyl sulfonic. Other acidic groups are nitro, chloro, or other halogenated groups, sulfonic, sulfate. It is to be noted that any homologues could be used and that cyclic, or benzenoid groups may be included-also derivatives of these compounds, such as salts, esters, amides, and the like. Examples of polar alkaline substituted mercaptans are: Mercaptan containing amino groups, which may be. primary, as, for example, p-amino ethyl mercaptan, or, secondary, as. for example, p-mercapto-ethyl-methyl amine or tertiary, as, for example, B-mercapto ethyl di-methyl amine. Other alkaline groups are imines and nitrogen heterocyclic compounds. It is to be noted that any homologues could be used and that cyclic, or benzenoid groups may be included-also de rivatives of these compounds,'such as salts, nitrogen derivatives, amides, and the like.'

On the other hand, the molecule may contain non-polar groups. An example of a mercaptan containing the non-polar hydroxyl group is the simple mercapto-carbinol compound, c-mercaptoethyl alcohol. An example of mercaptans containing non-polar aldehyde groups is the simple mercapto-carbinol, mercapto acetaldehyde'. An

.example of mercaptan containing non-polar ketone groups is the simple mercapto-carbonyl, mercapto-di-methyl ketone. An example of mer captan containing ester groups is the simple mercapto-ester, mercapto ethyl acetate. As an example of mercaptan containing ether groups is the simple mercapto-ether, c-mercapto di-ethyl ether. Homologues, cyclic or benzenoid and other derivatives of these compounds could be used.

Many other compounds could be listed such as the mercaptan containing more'than one substituted group such as, for example, 3 amino=2'hydroxy propyl mercaptan.

Many other mercaptan compounds could be included under the groups above and the following lists are given to show the wide variety of mercaptans which ma be used and to show that mercaptans having poly mercaptoand'poly sub stituted groups may be used: 1. Thioglycerol, mono, di-, or polythio-polyhydric alcohols, e. g., trithio hexitols, monoand polythio-polyoxyethylene glycols (e; g., tetra glycol dimercaptan) 2. mercapto-ethylhydroxy ethylamine, triomercapto-ethyl amine; 3. mono,'di-,'and polythio-polyhydroxyacids; 4. mercapto diand polycarboxylic acids, mono-, diand trithio mucic acids, monodimercapto succinic--acid, thiocitric'acid, mercaptoaminoacids; 5. alpha mercapto-methyl furane, thiophene, pyrrole, pyrimidine, thiofurfuralcohol 9'6. mercapto alkyl pseudo thioureas; 7. mercaptoalkylureas and thioureas; 8, mercaptoethyl urethane, mercaptoethylacetamide, mercapto ethyl guanidine, mercaptoalkyl 'betains and taurines. 4 I have discovered that all of the materials mentioned above function satisfactorily as hair wav- The concentration is usually less than 15%.- I have found that the mercaptans are especially effective when 'the pH range 'is'from 7.0 to l0.0-,--the preferred pH being about 9.2. I

I have found that all alkaline materials are satisfactory for adjusting these pHs-but that particularly effective with less hair destructive effeet are bases having a dissociation constant less than 5X1O- ;and preferably about- 10- In the cold wavingprocess also I have found the volatile bases, such as ammonia, methylamine,

and ethylamine are to be preferred with'the mercaptans, since at'the same pHval'ue and mercaptan concentration solutions containing these volatile bases. give tighter waves. Ammonia, therefore, is particularly to be preferred with the mercaptans since its ionization constantissatisfactory, its odor blends pleasantly with the mercaptans and it has a relatively non-irritating action in the desired pHrange of 7.0 to 10.0.

This pH range is particularly critical when the waving agent is used for that type of waving employing a chemical setting agent, as in the socalled "cold waving method, since in that system the necessary requirement of speed without hair destruction demands a high concentration of the waving agent in the waving solution. If the pH value is not high enough slow waving action will result and if too high the hair will be destroyed or badly damaged. While with sulfite a shorter waving time may require a pH of or above, with these more powerful waving agents, the use of pHs higher than 9.5 must be watched very carefully for with pH of 10 or above, hair destruction or injury may occur before a satisfactory wave is obtained.

It is to be noted that organic sulfides and disulfldes are not effective waving agents.

I have discovered that whereas all the mercaptans function very effectively in permanent waving where the final set is accomplished by heating and then cooling, when used in the socalled cold waving method requiring a chemical setting solution, unusual and startling differences from the prior art become apparent.

I have discovered that from the point of view of efiiciency waving action, the least effective comusing a mercaptan having non-polar groups such as glyceryl mono mercaptan.

Furthermore, I have found that mercaptans containing polar groups are difhcult to remove from the hair and whenever the hair becomes damp, for instance, in bathing, shampooing, or at sports such as skiing, the residual odor tends to offend. This is most observable with mercaptans containing polar alkaline groups such as 8- amino ethyl mercaptan.

This odor effect is thus of tremendous importance, not only during the processing of the wave, but for a long time after the wave has been given. As stated above, the bad odor and other disadvantages of the simple mercaptans can be obviated by having the organic group R of the mercaptan molecule contain either polar or nonpolar groups. By the term vapor-pressure-depressing substituent in the organic group R" of the mercaptan formula R-SH, is meant a substituted mercaptan which contains in its organic group R either a polar (ionizing) group or a nonpolar (non-ionizing) group of the type above described. I have found that whereas certain groups such as polar groups tend to reduce the vapor pressure of the mercaptan and thus make the resulting mercaptan less objectionable, nevertheless the malodor, although much fainter, tends to persist. I have discovered, however, that while the non-polar groups may be less effective in reducing the vapor pressure yet they change the resulting odor by the sweetening action of their groups. For example, to illustrate the sweetening power of the hydroxyl group, thioglycerol is much sweeter thanv thio-propyle'ne glycol which in turn issweeter thanfthe 'propyl mercaptan. Also," other non -polar groups, such as ethers, aldehydes, ketones and esters are effective, as is illustrated by the effect of the ether linkage of the following related compounds. Increasingly pleasant to smell are diglycol di-mercaptan, triglycol dimercaptan, tetra'glycol dimercaptan.

I have also discovered that as the molecular ticularly water-solubilizing groups, such as the hydroxy and ether groups thereof. For example, on a basis of odor, waving strength, and toxicity, these compounds in cold waving" particularly, are far more desirable and effective than ammonium hydrogen sulfide, which has heretofore been utilized particularly for cold waving. Actually, not only do these non-polar mercaptans give better waving results and lackv bad odor but also they are easier to remove from the hair and can be completely removed by shampooing or by thoroughly rinsing with water, no malodor being detected on the hair. More important, is that their easy removal allows practically no retention by the hair to effect a relaxation or loosening of the permanent wave with each succeeding wetting of the hair.

This very important feature of not losing its curl, once the hair is waved, and the imparting of an excellent elasticity to the curl and a fine lustrous natural gloss, result in a more natural appearance than has been possible with prior hair waving treatments. Particularly effective are the mercaptans. containing more than one watersolubilizing group as, for example, the polyhydroxy mercaptan, e. g., thio-glycerol (glyceryl monomercaptan). This substances great value, on an equivalent SH basis is shown by the fact that it is several times as powerful in waving value as ammonium hydrogen sulfide.

As illustrations of waving solutions using the new waving agents according to this invention, the following specific examples are given:

EXAMPLE 1 Polar type-Acidic Mercapto-acetic gms 10 Ammonium hydroxide cc 10 Water q. s cc EXAMPLE 2 Non-polar type Glyceryl monomercaptan gms 5 Ammonium hydroxide cc 2.5 Water q. s cc 100 EXAMPLE 3 Polar typeBasic Mercapto ethylamine gms 5 Water q. s cc 100 The waving solution in any of the above examples may be utilized for effecting a cold wave" by acid or the like. I have found that it is desirable to remove as much of the solutlon of the waving agent as possible by first rinsing with water. I have discovered that with mercaptans containing water-solubilizing non-polar groups, such as glyceryl monomercaptan, so complete is the removal by water alone that excellent non-relaxing waves can be obtained without the need for addiduced was not as strong as that given with the waving solutions of Examples 2 and 3.

The hair treated with the solution of Example 3, which needed no ammonium hydroxide added,

did, however, tend to retain an odor noticeable upon wetting the hair While with the solution of Example 2 not a trace of bad odor was present even when the waved hair was re-wetted. For more effective washing out of the mercapto-containing amines from the hair, it is possible tohave additional groups such as hydroxyl present. Particularly effective as such a compound is 2-hydroxy 3-amino propyl mercaptan.

Thus it is seen that mercaptans containing polar and non-polar groups may be used. It has been brought out hereinbefore that either polar or non-polar groups are within the spirit and scope of this invention. Polar groups differ from non-polar in that in water solution they may ionize.

If any of the above examples are used for waving where heat is employed, the concentration of the waving agent may be materially decreased, approximately to one-third or one-fifth of the concentration given in the examples.

Thus, for waving where heat is employed, the concentrations of the waving agents given in the above examples, so decreased, would be:

EXAMPLE 1 Polar typ -Acidic Mercapto-acetic, about 2 gms. to 3.3 gms.

EXAMPLE 2 Non-polar type Glyceryl monomercaptan, about 1 gm. to 1.66 gms.

EXAMPLE 3 Polar type-Basic Mercapto ethylamine, about 1 gm. to 1.66 gms.

In considering this invention, it must also be borne in mind that a purpose is to provide a waving agent for use in a solution, the concentration of the waving agent being much lower than heretofore effective commensurate with the desired effect of waving the hair.

As a comparison of the reduction of concentration of the waving ingredient provided by the instant invention as against that of one of the standard waving agents used in this art, namely, sodium sulfite, I have found that the same wave ing ingredient. Alternately, I can shorten the time of waving by using a stronger concentration but still below the concentrations heretofore used, for instance the sodium sulfite above mentioned. I, therefore, provide a complete control of the waving process by the waving agent.

Utilizing the waving solution of any of the examples, the following procedure, or one similar thereto, may be employed in giving a permanent wave: The head of hair is blocked off into secunder the same conditions of procedure can be tions and each of the sectioned strands is then well soaked in the waving solution. Thereafter, each section of hair is wound on a mandrel to the form desired and heat is then applied, as by a chemical heating pad arranged over the wound section or by an electrical heating unit, the temperature being raised to about 212 F.. and the hair, upon cooling, sets into its new configuration.

In giving a cold wave, procedures similar to the following, which may be variously modified, may be used: The head of hair is again sectioned off into strands which are preferably wound on mandrels, the waving solution being applied before or after winding by soaking the hair in any desired manner. After a suitable lapse of time for the reaction, the hair is water rinsed, and then a chemical rinse such as chlorine water may be applied which removes the last trace of the waving agent and thus assures the fixing of the hair in its new configuration, whereafter the hair will have a permanent wave. With an easily rinsable waving agent, such as glyceryl monomercaptan, this after rinse treatment is not necessary if proper water rinsing is employed.

I have found that in order to reduce the time of waving by this chemical method, i. e., without heat, to a figure comparable to the time of waving by heat it is necessary to increase the concentration of mercaptans in the waving solution about three to five times. Thus, the con centrations of mercaptans in the above examples, when so increased from the concentrations suitable for waving with heat, would be as follows:

EXAMPLE 1 PoZar-type-Acidic Mercapto-acetic, about 6 gms. to 10 gms.

EXAMPLE 2 Non-polar type Glyceryl monomercaptan, about 3 gms. to 5 gms.

to 8.3 gms.

EXAMPLE 3 Polar type-Basic Mercapto ethylamine, about 3 gms. to 5 gms. to

8.3 gms.

Thus, it is possible to so select the concentration of my novel waving agent in the waving solution that the desired time of actual treatment becomes feasible, ranging from a low concentration with longer time of application as is desired in some methods of cold waving, or a low concentration in continuous intimate contact with shorter time of application, or a low concentration with shorter time using heat, to higher concentrations with decrease in time whether the fix ation is by chemical, or by cooling subsequent to heating. Since the time of waving is greater with lower concentrations and less with higher concentrations of mercaptans and since, as described above, the time of waving is greater with a lower pH value and less with a higher pH value, it fol lows'that the concentration of "the mercaptan and the pH of the solution can be adjusted withinthe ranges given above to obtain a permanent change in the'configuration of human hair during 9, given time of application without damage to the hair structure by having the concentration of mercaptan in the higher portion of the concentration range for a lower pH and having the concentration of mercaptan in the lower portion of said concentration range for a higher pH. But I do not under any conditions use concentrations higher than heretofore used. On the contrary, comparing the time-concentration factors of my novel waving agent with waving agents of the prior art for equivalent purposes, it will be found that under all analogous conditions I provide a distinct reduction in concentration while attaining optimum results in the final waving.

While throughout this specification I have specifically mentioned the waving of hair, I do not wish ,to limit myself thereto, since by this invention it is possible to permanently alter or reform the form, shape or configuration of the hair as desired. Thus, my invention contemplates also the reverse of waving, such as dekinking, removal of curls or waves, imparting of creases and the like. Furthermore, it is not my intention to limit this invention or the term hair as used herein to treatment of human hair, but rather to include the treatment of any form of fiber structure which contains keratin. The waving solution according to this invention may be applied to the hair at any desired time, either before or after winding or otherwise mechanically placing the hair in its reformed desired shape or form and by any desired means, such assoaking, spraying, continuous circulation or the like, and the'claims are to be so construed. Furthermore, while I have described examples of my invention and have outlined advantages thereof over the prior art, I do not wish to limit myself to the exact materials or proportions given hereinbefore since a variety of like or similar materials may be used in lieu of those specified and the proportions thereof may be widely varied without departing from the spirit of my invention or the intended scope of the appended claims.

I claim:

1. A permanent waving composition comprising a mercaptan having a molecular weight less than 121 and having the general formula R-SH, where the organic group R contains a carbon atom attached to the sulfur atom, said mercaptan having a vapor-pressure-depressing substituent in the organic group R, in a solution containing an alkaline material having a dissociation constant less than 10- said solution having a pH higher than pH 7 and not higher than pH 9.5, the concentration of said mercaptan in terms of weight per volume ranging between about 1% and about 10%, the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application without damage to the hair structure by having the concentration of mercaptan in the higher portion of said concentration range for a lower pH and having the concentration of mercaptan in the lower portion of said concentration range for a higher pH within the stated pH range.

2. A permanent waving composition comprising a solution having a concentration in terms of weight per volume of 3% to less than about 8% of a mercaptan having a molecular weight less than 121 and having the general formula R-SH, where the organic group R contains .a carbon atom attached to the sulfur atom, said mercaptan having a vapor-pressure-depressing substituent in the organic group R, and a voltatile base having a dissociation constant less than 5 x 19- said solution having a pH ranging from about 9.2 to not higher than 9.5, the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application at temperaturestolerable to the human body without damage to the hair structure.

3, A permanent waving composition comprising a solution having a concentration in'terms of weight per volume of 3% to less than about 8% of a mercaptan having a molecular weight less than 121 and having the general formula R,SH. where the organic group R contains a carbon atom attached to the sulfur atom, said mercaptan having a vapor-pressure-depressing substituent in the organic group R, and an alkaline material having a dissbciation constant less than 5 lO said solution l aving a pH of about 9.2 to not higher than 9.5,the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application at temperatures tolerable to the human body without damage to the hair structure.

4. The method of permanently changing the configuration of human hair without damage to the hair structure, including the steps of imparting the vdesired configuration to the hair and treating of the hair for a length of time with a permanent waving solution comprising an alkaline material having a dissociation constant less than 5 10- and a mercaptan of the general formula R-SH where the organic group R contains a carbon atom attached to the sulfur atom, said mercaptan having a vapor-pressure-depressing substituent in the organic group R and having a molecular weight less than 121, said solution having a pH higher than pH 7 and not higher than pH 9.5, the concentration of the mercaptan in terms of weight per volume ranging between about 1% and about 10%, the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application without damage to the hair structure by having the concentration of mercaptan in thehigher portion of said concentration range for a lower pH and having the concentration of mercaptan inthe lower portion of said concentration range for a higher pH within the stated pH range; and then fixing said configuration.

5. The method of permanently changing the configuration of human hair without damage to the hair structure, including the steps of imparting the desired configuration to the hair and treating of the hair with a permanent waving solution comprising about 1% to about 10% in terms of weight per volume of a mercaptan of the general formula R-SH where the organic group R contains a carbon atom attached to the sulfur atom, said mercaptan having a non-ionizing vapor-pressure-depressing substituent in the organic group R, and an alkaline material having a dissociation constant less than 5 10- said solution having a pH higher than pH 7 and not higher than pH 9.5; the concentration of mercaptan and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application without damage to the hair structure by having .the concentration of mercaptan in the higher portion 01' said concentration range for a lower pH and having the concentration of mercaptan in the lower portion of said concentration range for a higher pH within the stated pH range; and then fixing said configuration.

6. A composition as specified in claim 1 wherein the vapor-pressure-depressing substituent is an ionizing group.

7. A composition as specified in claim 1 wherein the vapor-pressure-depressing substituent is an acidic group.

8. A composition as specified in claim 1 wherein the vapor-pressure-depressing substituent is a non-ionizing group.

9. A composition as specified in claim 1 wherein the vapor-pressure-depressing substituent is an ether group.

10. A composition as specified in claim 1 wherein the dissociation constant of the alkaline material is about 10- 11. A composition as specified in claim 3 wherein the dissociation constant of the alkaline material is about 12. A composition as specified in claim 3 wherein the concentration of mercaptan is about 6%.

13. A composition as specified in claim 3 wherein the vapor-pressure-depressing substituent is an ionizing group.

14. A composition as specified in claim 3 wherein the vapor-pressure-depressing substituent is an acidic group.

15. A composition as specified in claim 3 wherein the vapor-pressure-depressing substituent is a non-ionizing group.

16. A composition as specified in claim 3 wherein the vapor-pressure-depressing substituent is an ether group.

17. A permanent waving composition comprising a solution having a concentration in terms of weight per volume of about 1% to about 10% of a mercaptan having a molecular weight less than 121 and having the general formula RSH, I

where the organic group R contains a carbon atom attached to the sulfur atom, said mercaptan having a vapor-pressure-depressing substituent in the organic group R, and an alkaline material having a dissociation constant less than 5x10- said solution having a pH of about 9.2. the concentration of mercaptan being adjusted with respect to said pH to obtain a permanent change in the configuration of human hair during a given time of application at temperatures tolerable to the human body without damage to the hair structure.

18. A permanent waving composition comprising a mercaptan having a molecular weight less than 121 and having the general formula R-SH, where the organic group R contains a carbon atom attached to the sulfur atom, said mercaptan having a vapor-pressure-depressing substituent in the organic group R, in asolution containing an alkaline material having a dissociation constant less than 5x10 said solution having a pH higher than pH 7 and not higher than pH 9.5, the concentration of said mercaptan in terms of weight per volume being about 6%, and the pH of the solution being adjusted within said ranges to obtain a permanent change in the configuration of human hair during a given time of application without damage to the hair structure.

EVERE'I'I G. McDONOUGI-I.

REFERENCES CITED The following references are of record in the file or this patent:

UNITED STATES PATENTS OTHER. REFERENCES Schoberl, thru Chemical Abstracts, vol. 33, p. 964, Berichte, vol. 71B, 1938, pp. 2361-71.

Smith, thru Chemical Abstracts, vol. 30, page 4465, Preparation of a. Monothioglycerol," Berichte, vol. 693, 1936, pages 678-80.

Rheinboldt, thru Chemical Abstracts, vol. 31, pages 4270-1, Thioglyoerols, Berichte, vol. 7013, 1937, pages 675-80.

Pillemer et al., The Specificity of Keratins, Journal of Experimental Medicine, 1939, pp. 191- 197.

Rheinboldt, Uber Thioglycerine," Berichte, vol. B, 1937, pages 675-680 (page 677 especially pertinent).

Goddard and Michaelis, Derivatives of Keratin," Journal of Biological Chemistry, vol. 112 (1935-1936), pp. 361-371.

Turley and Windus, The Unhairing Problem," Stiasny-Festschrift, 1937, pp. 396-406 (page 400 especially pertinent).

Windus and Turley, The Unhairing Problem," Journal of the American Leather Chemists Association, vol. 33 (1938) DD. 246-253.

Speakman, The Chemistry of Wool and Related Fibres, Journal of the Textile Institute, Transactions, July 1941 (page T84 especially pertinent).

Goddard and Michaelis, A Study on Keratin, Journal of Biological Chemistry, vol. 106 (1934), pages 605-614.

Merck Index, Fifth Edition, 1940, page 185, entry cysteine." 

4. THE METHOD OF PERMANENTLY CHANGING THE CONFIGURATION OF HUMAN HAIR WITHOUT DAMAGE TO THE HAIR STRUCTURE, INCLUDING THE STEPS OF IMPARTING THE DESIRED CONFIGURATION TO THE HAIR AND TREATING OF THE HAIR FOR A LENGTH OF TIME WITH A PERMANENT WAVING SOLUTION COMPRISING AN ALKALINE MATERIAL HAVING A DISSOCIATION CONSTANT LESS THAN 5X10-3 AND A MERCAPTAN OF THE GENERAL FORMULA R-SH WHERE THE ORGANIC GROUP R CONTAINS A CARBON ATOM ATTACHED TO THE SULFUR ATOM, SAID MERCAPTAN HAVING A VAPOR-PRESSURE-DEPRESSING SUBSTITUENT IN THE ORGANIC GROUP R AND HAVING A MOLECULAR WEIGHT LESS THAN 121, SAID SOLUTION HAVING A PH HIGHER THAN PH 7 AND NOT HIGHER THAN PH 9.5, THE CONCENTRATION OF THE MERCAPTAN IN TERMS OF WEIGHT PER VOLUME RANGING BETWEEN ABOUT 1% AND ABOUT 10%, THE CONCENTRATION OF MERCAPTAN AND THE PH OF THE SOLUTION BEING ADJUSTED WITHIN SAID RANGES TO OBTAIN A PERNAMENT CHANGE IN THE CONFIGURATION OF HUMAN HAIR DURING A GIVEN TIME OF APPLICATION WITHOUT DAMAGE TO THE HAIR STRUCTURE BY HAVING THE CONCENTRATION OF MERCAPTAN IN THE HIGHER PORTION OF SAID CONCENTRATION RANGE FOR A LOWER PH AND HAVING THE CONCENTRATION OF MERCAPTAN IN THE LOWER PORTION OF SAID CONCENTRATION RANGE FOR A HIGHER PH WITHIN THE STATED PH RANGE; AND THEN FIXING SAID CONFIGURATION. 